The general objective of the proposed research is to extend the use of high resolution nuclear magnetic resonance as a non-invasive, in vivo probe of cellular processes and utilize its capabilities to study several specific problems in cell metabolism and physiology. Proposed work will consist of the following studies. 1) Measurement of relaxation parameters T1, T2, and nuclear Overhauser effect (NOE) of 13C, 31P and 1H nuclei of NMR detectable metabolites in a variety of cell types ranging from prokaryotes (E. coli) to single cell eukaryotes (S. cerevicia), to mammalian tissue (perfused hearts and liver) where the relaxation mechanisms may be different due to different intracellular conditions; exploration of the utility of contemporary pulse sequences for the detection of 13C resonances, and the development of new pulsed techniques by which proton resonances of hydrogens bonded to 13C labeled carbons are selectively observed from cells. These efforts are aimed at improving the sensitivity and the detection limits of NMR, which is generally the limiting factor in the cellular applications of this technique. 2) Development of tissue culture systems for 31P, 13C and 1H NMR studies with particular emphasis on questions involving hormone effects, comparison of normal, oncogenically transformed, and other cell lines with disorders. 3) 13C and 1H NMR studies on carbon metabolism in methane producing anaerobe Methanosarcina barkeri for the purpose of understanding methane production by these anaerobes, and biodegradation of halogenated phenols which are highly toxic compounds used throughout the world and which are catabolized by bacteria. 4) 31P and 13C NMR studies on the effect of cardiotonic drugs (in particular ARL 15BS, MDL 19000205 and amrinon) on the energetics and metabolism of perfused guinea pig hearts and heart failure models to be prepared from these animals. 5) Studies of the long term effects of these drugs on the heart energetics and metabolism in normal animals and animals with heart failure using whole animals and 31P chemical shift imaging; it is also anticipated that this work, in collaboration with the Department of Cardiology, University of Minnesota, will be extended to other clinical studies using animal models.